Fatty acids, C14-18 and C16-18-unsatd., Me esters

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Remarks:

read-across on structrual analogue

Adequacy of study:

key study

Study period:

november 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

read-across on structural analogue

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

Principles of method if other than guideline:

This method involves placing a quantity of sample in the sample chamber of the glassware and a suitable manometer liquid in the U-tube. The contents of the static glassware are connected to a vacuum system linked with pressure monitors to enable the reading of any pressure/ vacuum on the contents of the static glassware. The system is evacuated until optimum vacuum is observed.
The glassware is then isolated from the vacuum system. This is immediately followed by isolation of the sample chamber of the glassware so that any gas evolved from the sample will cause a displacement of the manometer liquid. When this is observed the levels of the
liquid in the manometer is balanced by introducing a positive pressure using an inert gas (typically nitrogen) or negative pressure (using vacuum). The total pressure on the sample after the levels of the liquid in the manometer is balanced is then registered on the display
unit coupled with the pressure transducers.
The glassware is then positioned in the constant temperature bath set to a desired starting temperature. As the static apparatus and its contents approaches temperature equilibrium in the bath, the levels of the manometer liquid are balanced using the positive
or negative pressure depending on the direction of displacement. This procedure is repeated until the system achieves temperature and pressure equilibrium (i.e. no significant change in temperature or pressure is observed). The temperature and pressure
displayed on the pressure monitors are then recorded. The temperature is subsequently set to a higher temperature (usually 5-25°C higher) and the procedure is repeated until enough data points are obtained.

GLP compliance:

no

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Type of method:

static method

Key result

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

7.26 Pa

Key result

Test no.:

#2

Temp.:

20 °C

Vapour pressure:

6.38 Pa

Vapour pressure:

40.23 Pa

Vapour pressure:

35.17 Pa

Run 1: 15.1 g of sample was placed under vacuum to degas with. Upon the application of

the vacuum, vigorous outgassing was observed. Analysis started after a total degas time

of approximately 64 hours. The vacuum at start of analysis was 0.0049 mbar.

Run 2: 14.6 g of sample was placed under vacuum to degas with stirring. Upon

application of the vacuum, a vigorous outgassing was observed. Analysis started after a

total degassing time of approximately 88 hours. The vacuum at start of analysis was

0.0047 mbar

Conclusions:

VP: 6.8 Pa at 20°C (mean of runs 1 & 2)

Executive summary:

The test is conducted in accordance with the procedure described in EU Regulation (EC) 440/2008, Annex Part A test A.4. As results the VP of the test item is 6.8 Pa at 20°C (mean of runs 1 & 2)

Key value for chemical safety assessment

Vapour pressure:

6.8 Pa

at the temperature of:

20 °C

Additional information

The test is conducted in accordance with the procedure described in EU Regulation (EC) 440/2008, Annex Part A test A.4. As results the VP of the test item is 6.8 Pa at 20°C (mean of runs 1 & 2)